Programmable Thermostats

Reviews of digital programmable thermostats

Lux TX9100E

Lux TX9100E

Click Here to find the Best Price on Amazon for the Lux TX9100E

List of Specifications:

  • 7 Day programming and 4 periods per day
  • Large mercury-free display with back light
  • Lux Products patented speed dial and ‘copy’ function
  • Smart Recovery (adaptive intelligent recovery)
  • Swing Control (up to 2.25 degrees in 0.25 increments)
  • Temporary override
  • Vacation mode
  • Batteries not needed
  • Filter warning
  • Can cycle fan
  • Keyboard lockout (10,000 plus combinations)
  • Display in Celsius or Fahrenheit & 12 or 24 hour clock
  • Energy Star approved
  • 1 year warranty
  • Price $40 (use the link above to check the latest price on Amazon)


  • Central air, heating only, cooling only, single stage  heat pumps, heat pumps with auxiliary, 2 wire hydronics, 3 wire hydronics, gas
  • up to 2 stages of heating and 1 stage of cooling


The Lux TX9100E 7 Day Universal Programmable Thermostat is a recommended programmable thermostat which is reliable and accurate and approved by Energy Star. It is similar to the Lux Products TX9000TS except that it doesn’t feature touchscreen programming. It does, however, come at an attractive price of just over $50 and it is compatible with a wider range of heating and cooling systems than the Lux Products TX9000TS.

The Lux TX9100E is a 7 day device that offers not only daily programs but also 4 programs per day. It can regulate gas, oil, electric, 2-Wire hydronic (hot water) systems and 3-wire zone valve hydronic (hot water) systems. It can also control single and multi stage heat pumps and up to 2 stages of heating and 1 stage of cooling. It can also draw its power from the mains (unlike the Lux Products TX9000TS).

Installation is straight forward  once you have read the instruction manual and it has a large mercury free display that can show the temperature in either Celsius or Fahrenheit and the time in either 12 or 24 hours styles. Programming is not hard to master and there is a handy copy function so you can repeat programs from one day to the next. As with most Lux Products thermostats, the Lux TX9100E also has an excellent keyboard lockout (with over 10,000 combinations) to stop anyone changing the settings.

The Lux TX9100E also has smart recovery to make sure the temperature set point is always reached at the start of a programmed period. There is also an adjustable swing control to let you set up a range around the temperature set point within which the thermostat doesn’t activate the heating or cooling. This is a useful feature to stop the HVAC short cycling.

There is also a temporary hold and unlike the Honeywell RTH7500D and Honeywell RTH7600D the Lux TX9100E also has a vacation mode so you can set a low heating/cooling program for while you are away and have the house comfortable for your return.


There is very little to find fault with this programmable thermostat. It represents excellent value for money at just over $50. If any improvements were to made it would be to allow the Lux TX9100E to regulate 2 stage cooling. Also the inclusion of an auto change-over function (to automatically switch between heating and cooling) would be appreciated by many consumers. And perhaps like the Lux Products TX9000TS a relative humidity monitor on the display would be useful.

Amazon Reviews

The Lux TX9100E 7 Day Universal Programmable Thermostat is the 15th best selling thermostat on Amazon. It has garnered 36 customer reviews. 28 people give the device 5 stars, 7 people give it 4 stars and only 1 person awarded a single star.

One happy customer commented how useful it was being able to set up when the second stage of the heat pump was activated because auxiliary heat is expensive. The same customer did note that the backlight could be brighter.

Another customer describes the Lux TX1500E as ‘extremely flexible’ and ‘super easy’ to install.

A lot of people comment about installation. These comments are mostly technical points about the specifics of different types of HVAC systems, heat pumps etc. One comment mentioned that Lux Products quickly responded with a wiring solution for his particular system. This positive comment about the customer service was repeated by several people.

One customer commented that being able to adjust the swing meant that the Lux TX9100E cycled his furnace just 2 or 3 times an hour compared to his old Honeywell unit which cycled the furnace 5 or 6 times an hour.

Keynote Quote:

“This is a highly flexible thermostat at a cheap price. I believe that Lux thermostats are top-rated by a leading consumer publication and I can see why. The customer service is great, the product works well and my sense is that it will last a long time based on the seemingly solid build quality. Highly recommended! ”

– Brad Willis

Wed, January 26 2011 » Lux Products, Under $50

Leave a Reply